1. Field of the Invention
The present invention relates to socket connectors for circuit boards. More particularly, it relates to card-edge sockets and connectors used within computer systems.
2. Description of the Related Art
Personal computer systems in general and IBM compatible personal computer systems in particular have attained widespread use. These personal computer systems now provide computing power to many segments of modem society. A personal computer system can usually be defined as a desktop, or portable microcomputer that includes a system unit having a system processor with associated volatile and nonvolatile memory, a display monitor, a keyboard, a hard disk storage device or other type of storage media such as a floppy disk drive or a compact disk read only memory (CD ROM) drive. One of the distinguishing characteristics of these systems is the use of a system board to electrically couple these components together. These personal computer systems are information handling systems which are designed primarily to give independent computing power to a single user or group of users and are inexpensively priced. One way of keeping the cost of computer systems down is to manufacture systems that use electrical parts in an efficient manner. Given the number of electrical devices in a computer system, such efficiency is paramount.
Modern multiple processor computer systems have sockets for multiple processors or microprocessors and require a termination card instead of a processor in situations in which a consumer orders a system that does not use each socket available for a processor on the computer system.
Referring to FIG. 1a, a typical multi-processor circuit board 101 is represented showing two processor sockets. The first socket connector 102 holds a typical PENTIUM-type processor 107. The second socket connector 103 holds a termination card 105 with termination resistors 106. FIG. 1b represents a typical termination card 105 for use in the socket connector 103. Conductive pads 108 and 110 shown in FIG. 1b are located on the back side of the termination card, and conductive pads 109 are on the front of the card. Also shown in FIG. 1b are termination resistors 106 and the conductive path leading to terminal voltage 108. Referring to FIG. 1c, a cross-sectional view of the socket connector 103 is shown as it would appear along the axis B from FIG. 1a. The signal pins 111 do not electrically couple when a termination card is not present.
Like computer systems that use sockets for processors, computer systems that use sockets to hold memory require a xe2x80x9ccontinuityxe2x80x9d circuit card to be installed in any socket not used for memory. Referring to FIGS. 1d and 1e, a multiple memory module designed system 600 is represented showing three memory socket connectors 602. Each socket connector 602 holds a memory module 605. A typical memory module is a RAMBUS INLINE MEMORY MODULE (RIMM). As shown in FIG. 1d, the memory controller 604, also called a xe2x80x9cmemory channelxe2x80x9d, is electrically coupled to all three memory module circuit cards 605 in series, terminating through termination resistors shown as 601 leading to termination voltage 603. Thus, the memory module circuit cards 605 do not require termination resistors. FIG. 1e represents a typical continuity circuit card 606 and a memory module circuit card 605 for use in the socket connector 602 shown in FIG. 1d. The conductive pads 608 shown in FIG. 1e are located on side A of the continuity circuit card 606. The conductive pads 609 are located on side B (not shown) of the continuity circuit card 606. Similar to the socket connector discussed above representing a conventional connector for multi-processor systems, the socket connector that requires use of a continuity module circuit card has signal pins inside the socket connector that do not electrically couple when a continuity circuit card or a memory module is not present.
What is needed is a system that does not require the extra expense of a termination card or a continuity card.
Accordingly, the present invention provides a socket connector and a card-edge that eliminates the need for either a termination card for multiple processor systems or a continuity card for systems holding multiple sockets for memory. The design of the socket connector connects a bus, which can be a memory bus, processor bus or any electrical signal, from one side of the socket connector to the other side of the socket by cross-connecting the signal through the signal pins when the socket is empty.